1. Field of the Invention
This invention relates to an archery training device for teaching an archer proper muscular control, muscle force and body positioning before, during, and after string release for accurate shooting of a bow and arrow. More specifically, the present invention promotes a balance between the archer's push-pull and the bow force while also providing feedback of this balance when shooting arrows.
2. Description of the Prior Art
An observer of an archer shooting a bow and arrow occasionally witnesses a flinching or collapsing of the archer's upper body during the process of releasing the bowstring. Obviously, such body movement or imbalance contributes to inconsistent and inaccurate shooting of an arrow with the bow. The importance of an archer practicing every day to improve his skills, and thereby minimize the tendency for collapse or imbalance has led to a need for training devices. For example, an archery training device was disclosed by Applicant in U.S. Pat. No. 4,887,584. However, U.S. Pat. No. 4,887,584 does not teach an archery training device that simultaneously allows an archer to shoot arrows in that a substantially inelastic force carrying member is employed. The inelastic force carrying member is suitable for isometric exercises, but artificially limits the archer's draw to the length of the inelastic force carrying member.
In contrast, U.S. Pat. No. 5,052,365, also in the name of Applicant, discloses an archery training device specifically adapted for use with a bow, with or without an arrow. However, using this archery training device with an arrow adversely affects the arrow's performance, making it unsuitable for use with an arrow for most practical purposes. U.S. Pat. No. 5,052,365 discusses in detail that the cause of this collapse is attributable to the archer having relaxed his or her upper back muscles during the initial stage of the shot so that the anchor hand (the hand used to draw the bowstring), bow hand, string arm elbow, or shoulders begin to move before the string fingers are completely free of the bowstring. This "reflex muscle relaxation" is an involuntary response, and, therefore, can only be shortened, but not eliminated entirely. To date, the above prior art has taught that compensation is possible under two approaches: shortening the period of time in which reflex muscle relaxation can influence the shot, and minimizing the effect of reflex muscle relaxation by improving the stance of the archer.
Ideally, for maximum stability while shooting an arrow, certain points of the archer's upper body frame should lie within a plane termed the "rigid frame plane". As can be seen in FIGS. 4 and 5, these points are the string arm or rear elbow joint 24 of the string arm 22, the anchor hand 34, the string or rear shoulder 23, the front shoulder 25 and the contact point of the bow hand 15 with the bow 14. The string arm elbow 24, the rear shoulder 23 and the contact point of the bow hand 15 with the bow 14 define the corners of a scalene triangle that establishes the rigid frame plane .alpha.. An archer properly maintaining the rigid frame plane a during the reflex muscle relax time will reduce movement of the string or anchor hand 34, bow hand 15, string arm elbow 24, and shoulders 23 and 25 in a manner which will improve shooting accuracy.
FIG. 1 shows the string arm elbow joint 24, the anchor hand 34 superimposed on the bow hand 15, and the string shoulder 23, indicated by points A, B and C, respectively, lying in the rigid grame plane .alpha.. Simultaneously, the anchor hand 34 and bow hand 15 lie in the bow plane .beta., which determines the lateral trajectory of the arrow. FIG. 2 illustrates a common defect in the stance of an archer 12 in which the string arm elbow 24 is outside the rigid frame plane .alpha. by some distance X. As a result, during the period in which the bowstring is being released, the anchor hand 34 ("B") is also forced out of the bow plane .beta., causing a significant error in the arrow's trajectory, as illustrated by FIG. 3.
In that the consequences of failing to attain the rigid frame plane .alpha. arise during the period between the beginning of the release of the bowstring and the time at which the string fingers are clear of the bowstring, this period is of primary importance in ascertaining the total effect of the rigid frame plane .alpha.. This period, in which the upper back muscles relax before the string fingers are free of the bowstring, has been termed the "reflex muscle relax time". The reflex muscle relax time begins when the string fingers start to open and ends when they are free of the forward pull exerted by the bowstring.
In general, the shorter the reflex muscle relax time, the less opportunity there will be for the collapse or otherwise adverse movement of the archer's bow hand 15, anchor hand 34, string arm elbow 24, and shoulders 23 and 25 outside of the rigid frame plane .alpha.. Consequently, a shorter reflex muscle relax time will enable the archer 12 to shoot more consistently and accurately even if the rigid frame plane .alpha. is not entirely achieved at the beginning of the shot. It also follows that proper muscular force and positioning of the anchor hand 34, string arm elbow 24, shoulders 23 and 25 and bow hand 15 within the rigid frame plane .alpha. during the reflex muscle relax time will also reduce the previously noted collapsing and imbalance of the archer's upper body, and thus promote more consistent and accurate shooting.
With reference again to FIGS. 4 and 5, the stance of the archer 12 at the start of the reflex muscle relax time is indicated at "D". As a result of failing to perfectly achieve the rigid frame plane .alpha. in conjunction with the reflex muscle relax time, the stance at the end of release, i.e. the end of the reflex muscle relax time, is altered as indicated at "E". Where no reflex muscle relax time occurs, the arrow's trajectory is indicated by a "zero relax line" 56. However, as a consequence of the inherent tendency to have reflex muscle relaxation and an imperfect rigid frame plane .alpha., the trajectory of the arrow is generally indicated by a "body relax line" 52.
U.S. Pat. No. 5,052,365, supra, provides an archery training device having an elastic member which is attachable to the archer's string elbow and the bowstring to induce a rapid increase in tension between the string elbow and the bow hand after release of the bowstring. The effect is to train the archer's muscles to remain taut throughout the shot to thereby minimize reflex muscle relaxation and thereby the adverse effect of the reflex muscle relax time. The archery training device provides the archer feedback regarding his or her upper body position and reflex muscle relax time after the bowstring release. This feedback is based on either an imbalance of forces exerted by upper back muscles which causes adverse movement of the anchor hand, bow hand, string arm elbow, and shoulders or an incorrect positioning of the bow hand, string arm elbow and shoulders. When the archer is properly positioned in the full draw position, the elastic member is positioned against his or her neck. However, if improper shifting of the upper body occurs during the shot due to a force imbalance, the elastic member shifts away from the side of the neck during release of the bowstring, a signal to the archer that he or she is not maintaining proper upper body positioning. If an arrow were to be shot at the time, this shifting would have an adverse effect on shooting accuracy. However, the device is not suitable for providing feedback when shooting an arrow because the elastic member is attached directly to the bowstring and the increasing tensional force generated by the elastic member on the bow string impairs the arrow's performance.
U.S. Pat. No. 4,887,584, supra, discloses a similar device with a first embodiment disclosing an inelastic force carrying member extended between the string arm elbow and the bowstring, while another embodiment includes an elastic member between the force carrying member and the bow handle to simulate the bow draw force in the archer's stance without the use of an actual bow. As with U.S. Pat. No. 5,052,365, these devices are intended for isometric exercise to train the archer's muscles to remain taut throughout the shot, which serves to minimize the effect of the reflex muscle relax time. However, the use of an inelastic force carrying member artificially limits the archer's draw to the length of the force carrying member. Even in the embodiment where an elastic member is attached between the force carrying member and the bow, the limited length of the elastic member provides almost negligible extension. Accordingly, none of the above devices are suitable for using when actually shooting an arrow, and all but the first embodiment is adapted for use without a bow.
In addition to the reflex muscle relax time, Applicant has determined that another critical aspect of shooting an arrow involves the push-pull balance between the bow hand 15 and the string arm elbow 24. More specifically, it is imperative that the pull force of the anchor hand 34 and the push force of the bow hand 15, which define a force line on the rigid frame plane .alpha., are balanced to assure stability and accuracy of the shot. Contrary to what one might think, the push and pull of the draw are independent of each other. As illustrated in FIG. 6, an archer's push-pull balance is defined with respect to the archer's spine 13. The front half push of the bowstring draw exists between the spine 13 and the bow hand 15, while the rear half pull of the draw exists between the spine 13 and the string elbow 24. The push-pull forces are designated to be either "dynamic" or "static." A dynamic force means contracting muscles that adapt to remain equal to the opposing bow force during bowstring release. A static force means contracting muscles that are less than the opposing bow force during bowstring release. The above is summarized in a pamphlet distributed by Applicant under the title "The Technical Side of Archery Form and the Formaster Training Device." R. F. Carella (1992), p. 5.
When balanced, the push-pull effect acts along the previously-noted body relax line 52 throughout the release cycle (unless zero reflex muscle relax time could be achieved --then, the push-pull effect would act along the zero relax line 56). Each half opposes the bow force with equal dynamic force during the release cycle. However, if each half of the push-pull does not have the same dynamic muscle force when the bowstring is released, the arrow's trajectory will follow a "force relax line" 54 which differs from the body relax line 52 as illustrated in FIGS. 7 and 8. FIG. 7 shows the effect of the pull being static, resulting in a collapse between the spine 13 and the string arm elbow 24 during the release of the bowstring, corresponding to the archer's aim being deflected to the left. FIG. 8 shows the effect of the push being static, resulting in a collapse between the spine 13 and the bow hand 15 during the release of the bowstring, corresponding to the archer's aim being shot to the right. In each case, the force relax line 54 deviates from the body relax line 52, thereby significantly affecting the arrow's trajectory, which compounds the effect of the reflex muscle relax time that establishes the body relax line 52.
It would be desirable to provide a device which can be used with an arrow, thereby enabling the use of the device during actual practice to improve the ability of the archer to maintain his or her push-pull balance in addition to sustaining the rigid frame plane while minimizing the reflex muscle relax time. U.S. Pat. No. 4,887,584, supra, was directed only at improving the stance for the rigid frame plane and muscle strengthening, and furthermore did not allow the use of an arrow. The archery training device taught by U.S. Pat. No. 5,052,365 was not suitable for shooting an arrow because the elastic member would impair the arrow's performance.
Accordingly, what is needed is an archery training device which aids in maintaining the push-pull balance of an archer's stance while also reducing the effects of the reflex muscle relax time and promoting proper positioning of the bow hand 15, string arm elbow 24, and shoulders 23 and 25 of the archer 12 within the rigid frame plane .alpha. when he or she is drawing and releasing the bowstring. In addition, what is needed is such an archery training device that will achieve the above aspects while also permitting the archer to shoot an arrow to allow the placement of the arrow to serve as a distinct form of feedback as to his or her push-pull balance and stance.